Method of making a web which is extensible in at least one direction

Abstract

A method includes the steps of co-extruding a first component and a second component. The first component has a recovery percentage R 1 and the second component has a recovery percentage R 2 , wherein R 1 is higher than R 2 . The first and second components are directed through a spin pack to form a plurality of continuous, molten fibers. The plurality of molten fibers is then routed through a quenching chamber to form a plurality of continuous cooled fibers. The plurality of continuous cooled fibers is then routed through a drawing unit to form a plurality of continuous, solid linear fibers. The linear fibers are then deposited onto a moving support, such ass a forming wire, to form an accumulation or fibers. The accumulation of fibers are stabilized and bonded to form a web. The web is then stretched by at least 50 percent in at least one direction before being allowed to relax. The relaxation of the web causes the fibers to acquire a 3-dimensional, coiled configuration which provides the web with extensibility in at least one direction.

1. A method of forming fibers into a web, comprising the steps of:
 a) co-extruding a first and a second component, said first component having a recovery percentage R 1  and said second component having a recovery percentage R 2 , wherein R 1  is higher than R 2 ;  
 b) directing said first and second components through a spin pack to form a plurality of continuous molten fibers each having a predetermined diameter;  
 c) routing said plurality of molten fibers through a quench chamber to form a plurality of cooled fibers;  
 d) routing said plurality of cooled fibers through a draw unit to form a plurality of linear fibers each having a smaller diameter than said molten fibers;  
 e) depositing said linear fibers onto a moving support to form an accumulation of fibers;  
 f) stabilizing and bonding said fibers to form a web;  
 g) stretching said web in at least one direction by at least 50 percent; and  
 h) allowing said stretched web to relax whereby said fibers acquire a 3-dimensional, coiled configuration which provides said web with extensibility in at least one direction.  
 
     
     
       2. The method of  claim 1  wherein said fibers are bicomponent fibers. 
     
     
       3. The method of  claim 2  wherein each of said bicomponent fibers has a core/sheath cross-sectional configuration. 
     
     
       4. The method of  claim 3  wherein each of said bicomponent fibers in said core/sheath cross-sectional configuration are mechanically adhered to one another. 
     
     
       5. The method of  claim 3  wherein each of said bicomponent fibers in said core/sheath cross-sectional configuration are chemically adhered to one another. 
     
     
       6. The method of  claim 3  wherein each of said bicomponent fibers in said core/sheath cross-sectional configuration are physically adhered to one another. 
     
     
       7. The method of  claim 1  wherein said web is a spunbond nonwoven web. 
     
     
       8. The method of  claim 1  wherein said web has an elongation of up to about 400% in at least one direction. 
     
     
       9. The method of  claim 1  wherein said first component has a volume percent in said web of from about 40% to about 80%. 
     
     
       10. A method of forming bicomponent fibers into a web, comprising the steps of:
 a) co-extruding a first and a second component, said first component having a recovery percentage R 1  and said second component having a recovery percentage R 2 , wherein R 1  is higher than R 2 ;  
 b) directing said first and second components through a spin pack at a first speed to form a plurality of continuous molten fibers each having a predetermined diameter;  
 c) routing said plurality of molten fibers through a quench chamber to form a plurality of cooled fibers;  
 d) routing said plurality of cooled fibers through a draw unit at a second speed, said second speed being greater than said first speed, to form a plurality of linear fibers each having a smaller diameter than said molten fibers;  
 e) depositing said linear fibers onto a moving support to form an accumulation of fibers;  
 f) directing hot air onto said accumulation of fibers to form stabilized fibers;  
 g) bonding said stabilized fibers to form a web;  
 h) stretching said web in both a machine direction and a cross direction by at least 50 percent; and  
 i) allowing said stretched web to relax whereby said fibers acquire a 3-dimensional, coiled configuration which provides said web with extensibility in two directions.  
 
     
     
       11. The method of  claim 10  wherein at least one bond per square inch is formed in said web. 
     
     
       12. The method of  claim 10  wherein at least 30 bonds per square inch are formed in said web. 
     
     
       13. The method of  claim 10  wherein said web is stretched from about 50 percent to about 500 percent. 
     
     
       14. The method of  claim 10  wherein said web is stretched from about 50 percent to about 250 percent. 
     
     
       15. The method of  claim 10  wherein each of said molten fibers has a predetermined diameter of from about 0.1 millimeter to about 2.0 millimeter. 
     
     
       16. The method of  claim 10  wherein said web has an elongation of up to about 200% in at least one direction. 
     
     
       17. The method of  claim 10  further comprising impinging said accumulation of fibers with a plurality of hot air streams to stabilize said fibers. 
     
     
       18. The method of  claim 10  wherein said first component is an elastomaric material. 
     
     
       19. The method of  claim 10  wherein said second component is polyolefin. 
     
     
       20. A method of forming bicomponent fibers into a web, comprising the steps of:
 a) co-extruding a first and a second component, said first component having a recovery percentage R 1  and said second component having a recovery percentage R 2 , wherein R 1  is higher than R 2 ;  
 b) directing said first and second components through a spin pack at a first speed to form a plurality of continuous molten fibers each having a predetermined diameter;  
 c) routing said plurality of molten fibers through a quench chamber to form a plurality of cooled fibers;  
 d) routing said plurality of cooled fibers through a draw unit at a second speed, said second speed being greater than said first speed, to form a plurality of linear fibers each having a smaller diameter than said molten fibers;  
 e) depositing said linear fibers onto a moving support to form an accumulation of fibers;  
 f) directing hot air onto said accumulation of fibers to form a stabilized web;  
 g) stretching said stabilized web in at least one direction by at least 50 percent;  
 h) allowing said stretched web to relax whereby said fibers acquire a 3-dimensional, coiled configuration; and  
 i) bonding said stretched web to form a web having extensibility in at least one direction.  
 
     
     
       21. The method of  claim 20  wherein some of said stabilized web is stretched in two directions. 
     
     
       22. The method of  claim 21  wherein said stabilized web is first stretched in a machine direction and then in a cross direction. 
     
     
       23. The method of  claim 20  wherein at least one bond per square inch is formed in said web. 
     
     
       24. The method of  claim 20  wherein at least 30 bonds per square inch are formed in said web. 
     
     
       25. The method of  claim 17  wherein said web has an elongation of up to about 100% in at least one direction. 
     
     
       26. The method of  claim 17  wherein said web has an elongation of up to about 400% in two directions.